1. Field of the Invention
The present invention relates to a display shelf and a display shelf system, and particularly, to a display shelf and a display shelf system having a transmission-type screen, and a projector which is capable of projecting a projector image on the basis of input data.
2. Discussion of the Background
A display shelf is used widely in retail shops, such as supermarkets, convenience stores, and department stores. In such retail shops, an article is displayed on the display shelf, and an inventory tag corresponding to the article is set in the display shelf for the purpose of giving information about a price of the article and so on to customers.
In recent years, an electric inventory tag has been developed (see Japanese Laid-Open Publication No. 2005-099888 and Japanese Laid-Open Publication No. Hei 7(1995)-17608). The electric inventory tag uses, for example, a liquid crystal panel or an organic EL panel (see paragraph [0008] of Japanese Laid-Open Publication No. 2005-099888).
Moreover, POP (Point-of-Purchase) advertising is used widely as a method for promoting the purchase of an article by bringing the article displayed on the display shelf to customers' attention. Japanese Laid-Open Publication No. 2001-245756 discloses a showcase (display shelf) which includes a projector and a transmission-type screen for displaying an image projected from the projector, on a ceiling of the showcase. This technique eliminates the need for attaching a POP advertisement made from a recording medium, such as paper, to the display shelf. Furthermore, the display effect of an article displayed on the display shelf can be enhanced by projecting a projector image on the screen (see paragraph [0018] of Japanese Laid-Open Publication No. 2001-245756).
Japanese Laid-Open Publication No. 2005-099888 and Japanese Laid-Open Publication No. Hei 7(1995)-17608 disclose a display shelf that displays a price or advertising on a flat display surface. Such a display surface is easily viewable when seen head-on. However, such a display surface is not easily viewable seen from the side (from a lateral direction of the display surface). Therefore, such a display surface is not easily viewable by a viewer approaching the display shelf from the side (from the lateral direction). Depending on the layout of the display shelf, many viewers may be positioned in the lateral direction (to the side) of the display shelf.